Earth anchor



Dec. 27, 1960 c. E. CLAPPER EARTH ANCHOR Filed JulyflO, 1959 M Il. iii! INVENTOR. 541/0@ i Klapper' BY Mg, M

United States Patent EARTH ANCHOR Clyde E. Clapper, Rte. 1, Box 73, Blue Springs, Mo.

Filed July 10, 1959, Ser. N0. 826,332

9 Claims. (Cl. 189--92) This invention relates to new and useful improvements in earth anchors, and has particular reference to an earth anchor having a stake-like body or housing and groundengaging means normally retracted within the housing and which are extendable laterally from the housing after said housing has been inserted in the earth.

An important object of the present invention is the provision of an earth anchor of the general class described having novel means providing for maximum extension of said ground-engaging means from said housing, and hence for maximum holding power of the anchor. The actual limitation of the degree of extension and area of the extended ground-engaging means is determined by the size of the ground-engaging means which may be fully retracted into the housing of the anchor preparatory to inserting the anchor into the ground. The accomplishment of this object therefore involves a novel arrangement of parts whereby ground-engaging means, constituting a pair of elongated fiukes, of maximum length may be retracted into and extended from a body member of a given size.

Another object is the provision of an earth anchor of the class described wherein the level of the ground-engaging dukes is closer to the bottom of the housing than in previous anchors of this type. This provides the greatest possible holding power when setting the anchor at any given depth, since the iiukes are thereby positioned farther below the surface of the ground.

A further object is a novel arrangement of parts whereby the ground-engaging flukes are solidly supported relative to the housing at all times, both during extension and retraction thereof, and also while fully extended, whereby to prevent damage to the anchor parts which might otherwise occur as a result of misarrangement of the linkes relative to the body.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, ease of assembly and servicing, and adaptability for use in a wide variety of applications.

With these objects in View, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

Fig. l is a side elevational view, partially broken away, of an earth anchor embodying the present invention, shown inserted operatively in the earth with the groundengaging dukes fully extended,

Fig. 2 is an enlarged longitudinal sectional view of the anchor as shown in Fig. l, with parts left in elevation and parts broken away,

Fig. 3 is a view similar to Fig. 2 but showing the dukes fully retracted within the housing,

Fig. 4 is a fragmentary sectional View taken on line IV-'IV of Fig. 3, with the housing in section and the remaining parts left in elevation, and

Fig. 5 is a sectional view taken on line V-V of Fig. 2, with parts left in elevation.

Like reference numerals apply to similar parts throughout the several views, and Athe numeral 2 applies to a ice rtubular body or housing formed of steel or other suitable material. The lower end of said housing is closed by an end fitting including a bottom plug 4, the external surface of which is spherically curved, and the upper surface of which has a countersunk socket 6 formed therein. A pair of tongues 8 formed integrally with plug 4 extend upwardly into housing 2. Externally said tongues are cylindrically curved and engage the housing wall at diametrically opposite sides thereof. The inner or confronting surfaces of said tongues are planar, being parallel to each other and to the axis of the housing. Plug 4 is secured in the housing by a pair of screws 10 (see Fig. 4) extending through the housing wall and threaded into tongues 8. A flat screw plate 12 is disposed between the upper end portions of tongues 8, at right angles to the housing axis, and is provided with a central threaded aperture 14 therein. Opposite edge portions of said screw plate are carried for horizontal sliding movement in grooves 16 (see Fig. 4) formed in the confronting faces of the tongues, and the housing secures said plate against removal from said grooves. The plate must of course be positioned in the grooves before the tongues are inserted into the housing.

The upper end of housing 2 is closed by a top plug i8 secured therein by screws 2i?, said plug having a central aperture 22 formed therein. A stem 24 is carried for rotation and axial sliding movement in aperture 22. An eye member 26 is aixed to the upper end of said stem, said eye serving both as a means for turning.

said stem to operate the iiukes as will be described, and also as a means for attaching a guy line or the like which is to be anchored relative to the ground by means of my device. Stem 24- extends downwardly through the housing coaxially therewith. The lower end portion of said stem is externally threaded at 2g with right-hand threads, and is screwed into and through aperture i4 of screw plate 12, which is correspondingly threaded. The lower end portion of said stem is also tubular, having an axial socket 30 formed therein from the lower end thereof, said socket being threaded with left-hand threads.

Threaded into socket 3@ is a correspondingly left-hand threaded spindle 32, said spindle extending downwardly from the stern between tongues S. Rigidly affixed to the lower end of said spindle is a cross head indicated generally by the numeral 34 and including a horizontally extending bar 36. The ends of said bar are planar, and bear slidably against the confronting faces of tongues 8, whereby rotation of the cross head and spindle about the housing axis is prevented. Extending oppositely from the midpoint of bar 36 are a pair of horizontal stub shafts 38, the outer ends of which rest in sliding engagement with .the inner surface of housing 2. Formed in the lower side of each of said stub shafts, adjacent the outer end thereof, is a notch 40, the purpose of which will presently be described. Depending from cross head 34 and rigidly connected thereto is a short finder pin 42 coaxial with the housing, and which is adapted to be received snugly in socket 6 of bottom plug 4, as will be described.

Each of stub shafts B supports a duke 44 comprising an elongated strip of plate metal having a width corresponding to the distance between the confronting faces of tongues 8, and being cylindrically curved from end to end. Referring principally to Figs. 3 and 4, it will be seen that when the fiukes are retracted within housing 2 they are disposed generally vertically, with their concave surfaces facing outwardly, and their convex surfaces abutting each other at the centerline of the housing. Adjacent its upper end, each iiuke has a hole 46 formed therethrough, through which the corresponding stub shaft 3S extends to support the fluke. Thus the duke may be moved slidably along the shaft, and also, due to the fact that the-hole is oversized, may be tilted relative to the through said eye.

axis of's'aid shaft. The lower end of each of the ukes extends` into a hole formed therefor in the wall of housing 2, and is provided with a curved cutting edge 43, which when the. ilukes are fully retracted as shown in Figs. 3 and 4 is disposed flush. with they outer surface of the housing. The two iiukes rest respectively onV apair of bevelled lips 52 formed by chamfering the upper surface of bottom plug 4 at diametrically opposite sides thereof.

In the operation of the anchor, it is rst inserted, with the ukes retracted, into a hole 54 which has previously been bored in the ground 5d by4 any suitable means, not shown as it forms no part of the present invention. The present device is not properly termed a stake, as it is not adapted to be driven into the ground by a hammer or the like. lt will be seen that by allowing the two liukes to abut each other as shown when fully retracted, the tlukes may be of the greatest possible arcuate length for the diameter of the housing. Since this increases the degree or distance to which the linkes may be extended, and the greater extension provides greater holding power of the anchor in the earth, this feature is a substantial improvement over previous anchors of this type wherein a stem or spindle extends between the dukes at all times.

After the anchor has been inserted in ground hole Sti, stem 24 is turned in a clockwise direction as viewed from above, either by manual manipulation of eye 215, or with the assistance of a lever bar, not shown, inserted This advances the stem downwardly through screw piate i2, by means of threads 28. Simultaneously, spindle 3'2 is advanced downwardly relative to the stem, since said spindle is threaded oppositely to the stem, and since the spindle is locked against rotation by the sliding engagement of the ends or" bar 35 of cross head 34 with tongues S. rfhus crosshead 34 is advanced downwardly at a rate equal to the sum of the leads of the stern and spindle threads. Assuming that the two threads Vhave equal leads, the cross head moves at double the rate of the stern. rhis reduces the stem travel and its maximum extension from the housing, and reduces the number of turns thereof requiredto extend the dukes.

As the cross head is lowered, stub shafts 3S thereof force dukes de downwardly, and the lower ends of said llukes are guided outwardly by bevelled lips 52 of bottom plug d, and the ukes are extended outwardly through holes 5t) of the housing, to the position shown in Figs. l, 2 and 5. The ukes are advanced along an arcuate path, their final extended position being roughly concentric with their retracted positions in the housing. ln this manner, any necessity that the flukes move transversely to their curved planes as they are extended is reduced to a minimum. This reduces the power required to extend said flukes, and provides that the elevation of the anchor in the earth hole 54 will not be changed as the dukes are extended.

As cross head 3d is lowered to extend the ukes as described above, it is guided against lateral deflection in the housing by the fact that the ends Vof bar thereof engage tongues 3, and the outer ends of stub shafts 3S engage the housing wall. This tends to prevent bending of spindle 32 should, for example, one of the dukes ce.' tact a Vstone or harder ground than the other fluke, which would cause the cross head to be pressed toward one side or the other of the housing. As the flukes near their fully extended positions, nder pin 42 enters socket 6 of bottorn plug d. This further braces the cross head against lateral deflection in the housinfy due to une ual forces applied to thefflukes by loads applied to the anchor.

When the ukes are fully extended, each uke is supshaft 38 of the cross head presses downwardly against the fluke at a point intermediate the two lower supportl points.

' Each duke is thus gripped securedly as in a vise. Also,

as the angularity of the Yuke to shaft 3S changes during extension of the duke, the portion of the iluke bounding the lower portion of hole 46 thereof enters and is engaged by notch 4t) in the lower edge of shaft 3S, as clearly `shown in Fig. 2. This corrects a weakness of previous anchors of this general type, which was that any force tending to pull the anchor from the ground tended to pivot the ukes about lips 52 ras a fulcium, tending to force the inner ends of the flukes upwardly and outwardly, with the result that said ilukes moved outwardly along the shafts and damaged or actually tore out the housing wall. Notches 4t) prevent any such outward movement of the flukes on the shafts, but do not interfere with the necessary freedom of movement of the llukes relative to said shafts.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. An earth anchor comprising an elongated tubular housing, an end fitting including a bottom plug fixed in the lower end of said housing and a screw plate xedly associated with said bottom plug and disposed in said housing in spacedy apart relation above said bottom plug, said housing having a pair of diametrically opposite openings formed therein just above said bottom plug, a top plug closing the upper end of said housing, a stem disposed axially in said housing, extending through an opening in said top plug and being threaded in said Yscrew plate, a cross head disposed intermediate said screw plate and said bottom plug, and beneath the lower end of said screw, means attaching said cross head to said stem whereby said cross head is advancedl toward said bottom plug by turning said stem in said screw plate, and a pair of elongated arcuately curved flukes supported at their upper ends by said cross head for pivotal movement on horizontal axes, and with their lower ends normally registering with said housing openings, said flukes being disposed with their concave sides facing outwardly and their convex sides abutting each other at the centerline of the housing when said flukes are disposed entirely within said housing, whereby as said cross head is lowered toward said bottom plug, said nukes will be extended outwardly through said openings.

2. An earth anchor as recited in claim l wherein said end fitting includes a pair of tongues extending from said bottom plug in spaced apart relation, and wherein said screw plate has edge portions thereof slidably engaged in grooves formed horizontally therefor in the confronting surfaces of said tongues, other edges of said screw plate engaging said housing whereby removal of said plate from said grooves is prevented.

3. An earth anchor as recited in claim l wherein said means attaching said cross head to said stem is freely rotatable about the axis of said stem, and wherein said end fitting includes tongue members extending between and rigidly interconnecting said bottom plug and said screw plate, said cross head having sliding engagement with said tongue members whereby rotation of the former is prevented, and whereby said llukes are maintained in alignment with said housing openings.

4. An earth anchor as recited in claim 1 wherein said means attaching said cross head to said stem includes a spindle xed to said cross head and coaxial with said stem, said spindle being threaded to said stem by threads opposite to those connecting said stem to said screw plate, and with the addition of means for preventing rotation of said cross head and spindle relative to said housing.

5. An earth anchor as recited in claim l wherein said cross head includes a cross bar extending laterally .of said housing and a pairof horizontal stub shafts extending oppositely from said cross bar, each of said iiukes having a hole` formed therein through which one` of ,said shafts extends to support said fluke, said hole being of suciently large size to permit angular pivoting of said fluke relative to said shaft on a horizontal axis, as well as movement of said fluke longitudinally along said shaft.

6. An earth anchor as recited in claim 5 wherein the outer ends of said stub shafts and said cross bar rest in sliding engagement with said housing and with portions of said end tting for movement longitudinally of said housing, whereby deflection of said cross head laterally in said housing is prevented.

7. An earth anchor as recited in claim 5 wherein said means attaching said cross head to said stem is freely rotatable about the axis of said stem, and wherein said end tting includes tongue members extending between and fixed to said bottom plug and said screw plate, and wherein the outer ends of said cross bar rest in sliding engagement with said tongues for movement longitudinally of the housing, whereby to prevent rotation of said cross head in said housing, and wherein the outer ends of said stub shafts are in sliding engagement with the inner surfaces of said housing.

8. An earth anchor as recited in claim 5 wherein each of said stub shafts is provided with a notch in the lower side thereof adjacent the outer end thereof, whereby as the fluke supported thereby is extended from said housing and consequently tilted about a horizontal axis relative to said shaft, a portion of the fluke bounding the hole through which said shaft extends will enter said notch, whereby said uke is prevented from moving outwardly relative to said shaft.

9. An earth anchor as recited in claim l wherein said cross head and said bottom plug are provided one with a finder pin extending axially of the housing and the other with a matching socket, said pin being suiciently short as not to hold said ukes out of abutting relation when said ukes are retracted within said housing, whereby as said cross head approaches said bottom plug during extension of said flukes, said nder pin will enter said socket to brace said cross head against deflection laterally of said housing.

Green et al. Mar. 10, 1931 'Clapper Dec. 9, 1958 

